Mestrado em Geotecnia, Estruturas e Construção Civil (EECA)
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Navegando Mestrado em Geotecnia, Estruturas e Construção Civil (EECA) por Por Orientador "CARASEK, Helena"
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Item Estudo da propriedade resistência superficial em revestimentos de argamassa(Universidade Federal de Goiás, 2009-09-20) ALVES, Amália Silva; CASCUDO, Oswaldo; http://lattes.cnpq.br/3336749062812376; CARASEK, Helena; http://lattes.cnpq.br/3023241186996790The lack of cohesion in mortar renderings corresponds to the loss of mechanical strength among theirs layers due to the weakening of particles bond, a fact which is reflected, among other events, by a low surface resistance of these renderings. Thus, poor surface strength of mortar renderings accelerates their degradation process, leading to a significant reduction in the level of their performance and leading to failures in the functions assigned to them. In this context, this basically experimental research aimed to study the property of surface strength in mortar renderings. So, was investigated the applicability of some test techniques, pendulum hammer, dynamometer traction and ultrasounds (by indirect method) to evaluate surface characteristics of the mortar renderings. In addition, were also evaluated the effects of moisture absorbed by the renderings, the influences of composition, air entrained content and application way in the surface strength of the mortar renderings. In this study, the experimental program was divided into two stages. In the first stage, were used: one mortar mixed (cement: lime: sand) and one industrial mortar (with air entrained content equal 20%) applied in one type of substrate (concrete surface - standard substrate ABCP) by compressed air projection, so that their produced coverings were tested under different conditions of moisture (oven-dry, dry environment, wet and saturated). In the second stage, were used: one mortar mixed (cement: lime: sand) and three industrial mortars (with air entrained content equal 20%, 30% and 40%) applied to the substrate standard in three ways (manually, by means fall box and by compressed air projection). Using statistical criteria, the main results have shown a significant effect of the four mentioned factors on the surface strength, in view of the testing techniques used. However, only showed no significant the effect of moisture in the hardness index.Item A influência das condições climáticas na durabilidade dos revestimentos de fachada: estudo de caso na cidade de Goiânia GO(Universidade Federal de Goiás, 2012-08-29) FREITAS, Juliana Gomes de; CASCUDO, Oswaldo; http://lattes.cnpq.br/3336749062812376; CARASEK, Helena; http://lattes.cnpq.br/3023241186996790The climatic elements are related to the deterioration of the facades of buildings. Understanding the joint action of rain, wind and sunshine is important for prevention of pathological manifestations, thus ensuring the durability of coatings. Then, it becomes essential to know about the mechanisms of heat and moisture in porous materials. The problems related to this phenomenon are many, including the dimensional variation, which can cause cracks. The solar orientation and the presence of architectural details on the facades can cause the existence of the wettest spots, which favors the deposition of pollutants and microorganisms, causing stains. Thus, this paper aims at analyzing and understanding of issues that address the durability of facade coatings based on the understanding of the influence of climatic factors in buildings of the School of Engineering of the Federal University of Goiás (UFG), in Goiânia. Methodologically, the study aimed to: conducting a survey in order to quantify and map the pathological manifestations present, measurements of surface temperature and humidity in the dry and rainy seasons, trying to relate them to the cardinal orientations, creation of maps of wind-driven rain using data from the meteorological station of UFG, and conducting thermographic images, also in the rainy and dry seasons. The main results, it was found that the facades are exposed to different levels of humidity and temperature, which may favor the further deterioration of these. It was found that the north façade is the one that receives more sunlight in both the rainy and dry season, contributing to a high rate of fissuration. The same orientation is also one of the most humid and with higher levels of staining, consolidated information through wind-driven rain, that in the months of January and February 2012 reached one of the highest values. It was also observed that among the sites chosen for the measurements of surface moisture and temperature, the more prone to deterioration are the architectural details, as reached the highest values. In relation to infrared thermography, it was found that the best time of year for inspections was in the dry season and in the afternoon. In these periods, it was possible to identify pathological manifestations in the facades, such as stains, cracks and fantômes. An example is the case of the cracks which had a temperature 1°C lower than the part of the masonry without defects. It was also possible to visualize moist spots, as well as the lining of the points that were on the masonry and structure.Item Estudo do mecanismo de aderência de azulejos e argamassas de cal em revestimentos históricos(Universidade Federal de Goiás, 2011-05-16) JAPIASSÚ, Pammila; CARASEK, Helena; http://lattes.cnpq.br/3023241186996790The historical glazed tiles facades are an important luso-brazilian cultural expression that must be conserved and preserved. The bonding loss of glazed tiles to laying mortars is one of the most critical pathologic manifestations of this kind of coating. However, despite this importance, there‟s still a lack of studies about the bonding mechanism between this historical components. Accordingly, this dissertation proposed to perform an experimental and exploratory research, which the main objective is to give some contribution to the understanding of the ancient tile‟s bonding mechanism to the aerial lime-based mortar of historical buildings facade. For this, were analyzed samples of facade historical ceramic coating, between the late XIX and early XX century, of Ovar‟s buildings, in Portugal. In order to reproduce the historical bonding mechanism, were also analyzed ceramic coating applied in laboratory studying mortars of rehabilitation. In the first stage, were analyzed the ceramic coating and the mortars historic of three cases, as well was performed the interface‟s study between this two materials. In the second stage, were produced ceramic coatings in laboratory using tiles (similar to the historical ones) and four types of mortars of rehabilitation, composed by aerial lime, metakaolin and sand, varying the content of pozolana in 0%, 5%, 10% e 15%, replacement of lime in volume. In this stage, were characterized the tile, the raw materials of the mortar, and mortar in the fresh and hardened. Finally, yet was studied the interface between the glazed tile and the mortar of rehabilitation, in order to compare this one to the historical one. It was observed in the analysis of the historical ceramic coatings that the values of bond strength and of extension of bond were more related to the agregates granulometry than to the binder/aggregate of the laying mortars. In the case of the ceramic coatings molded in laboratory, it was found the influence of the metakaolin content in the rehabilitation mortars in bond strength. It was also observed a possible influence of the shape of the tile‟s back surface in the bonding of ceramic coatings. By the analysis in the SEM was identified the morphology of the products of carbonation and possible pozzolanic reactions in the studied mortars, that contributing to the increased bond strength of these materials.Item Influência da chuva dirigida e dos detalhes arquitetônicos na durabilidade de revestimentos de fachada(Universidade Federal de Goiás, 2010-05-21) MELO JÚNIOR, Carlos Mariano; CARASEK, Helena; http://lattes.cnpq.br/3023241186996790The durability of the facades is related to performance against the deleterious effects of climatic elements, among them the wind driven rain, and the effects provided by the elements presents in building facades. Understanding these aspects is important for the prevention of pathological manifestations, increasing the capacity of the building to perform his functions for a long period. The presence of architectural and construction details can act as protective barriers or conductive elements of moisture from rain, well as a platform for deposition of pollutants and microorganisms, causing staining of the facades. Thus, this paper aims to point out the influences of wind driven rain and elements of facades of the durability of the facades of buildings located in Goiania-GO, related them to the cardinal points North, South, East and West. Methodologically, the paper seeks to: creation of the first maps of wind-driven rain to the city of Goiania, with data obtained from the National Institute of Meteorology in the period of 2002 to 2008; carrying out measurements of surfaces moisture on the four facades of the local building with mixed mortar rendering; data collection of cases of infiltration along the technical assistance for builders, relating them to their respective guidelines; identification of microorganisms collected on the façade elements and visual inspection with photographic record of the facades staining due to the inefficiency of the architectural and construction details. As main results, it was found that the infiltration and staining occur differently for each façade, due mainly, the specific climate of the city of Goiania. From the analysis of the results of the indices of wind driven rain, it was found that the facades oriented toward the North are more susceptible to moisture penetration by cracks and openings, fact also confirmed by the survey of cases of infiltration. For the identification of microorganisms, it was observed that facades face South tend to favor the growth of fungi, while the others showed the growth of phototrophs, justified by the increased incidence of the sunlight on these facades and the staining described generically as dirt due the pollutions are also the presence of microorganisms. From the standpoint of staining, observed an increased formation of spots near the region of window sill and dripping on the facades facing the South direction and greater presence of staining on the parapets of the facades facing the North directions. The fantômes occurred more frequently in walls of the South facades.Item Efeito do Ar Incorporado em Argamassas de Revestimentos(Universidade Federal de Goiás, 2010-10-29) RESENDE, Paulo Sérgio de Oliveira; CARASEK, Helena; http://lattes.cnpq.br/3023241186996790The present study contemplates in a scient ific way the act ion of air ent raining agents in mortars produced in laboratory and the ef fects on the coat ings appl ied on porous subst rates (ceramic blocks, concrete blocks) . This is an experimental work, aiming to test the effect of the air entraining agents in fresh mortars, hardened state and the remaining ai r in coat ing appl ied. The variables were: ai r content , type of subst rate and sur face finishing. Adopt ing a methodology for varying levels of ent raining ai r, keeping fixed the subst rate, the form of appl icat ion and the type of sur face finishing, evaluat ing the propert ies of mortars in order to obtain the ideal air content of dosage. Other studies were done after evaluat ion of opt imal ai r content , keeping i t as a fixed condi t ion and varying the type of subst rate, appl icat ion type and the type of sur face finishing, in order to analyze thei r inter f erence in the amount of remaining ai r, as wel l as such inter ference coat ing appl ied.